SNMP_CONFIG



SNMP_CONFIG

NAME
DESCRIPTION
DIRECTORIES SEARCHED
CONFIGURATION FILE TYPES
SWITCHING CONFIGURATION TYPES IN MID-FILE
COMMENTS
INCLUDING OTHER CONFIGURATION FILES
API INTERFACE
SEE ALSO

NAME

snmp_config - handling of Net-SNMP configuration files

DESCRIPTION

The Net-SNMP package uses various configuration files to configure its applications. This manual page merely describes the overall nature of them, so that the other manual pages don’t have to.

DIRECTORIES SEARCHED

First off, there are numerous places that configuration files can be found and read from. By default, the applications look for configuration files in the following 4 directories, in order: /etc/snmp, /usr/share/snmp, /usr/lib64/snmp, and $HOME/.snmp. In each of these directories, it looks for files with the extension of both conf and local.conf (reading the second ones last). In this manner, there are 8 default places a configuration file can exist for any given configuration file type.

Additionally, the above default search path can be overridden by setting the environment variable SNMPCONFPATH to a colon-separated list of directories to search for. The path for the persistent data should be included when running applications that use persistent storage, such as snmpd.

Applications will read persistent configuration files in the following order of preference:

file in SNMP_PERSISTENT_FILE environment variable

directories in SNMPCONFPATH environment variable

directory defined by persistentDir snmp.conf variable

directory in SNMP_PERSISTENT_DIR environment variable

default /var/lib/net-snmp directory

Finally, applications will write persistent configuration files in the following order of preference:

file in SNMP_PERSISTENT_FILE environment variable

directory defined by persistentDir snmp.conf variable

directory in SNMP_PERSISTENT_DIR environment variable

default /var/lib/net-snmp directory

Note: When using SNMP_PERSISTENT_FILE, the filename should match the application name. For example, /var/net-snmp/snmpd.conf.

CONFIGURATION FILE TYPES

Each application may use multiple configuration files, which will configure various different aspects of the application. For instance, the SNMP agent (snmpd) knows how to understand configuration directives in both the snmpd.conf and the snmp.conf files. In fact, most applications understand how to read the contents of the snmp.conf files. Note, however, that configuration directives understood in one file may not be understood in another file. For further information, read the associated manual page with each configuration file type. Also, most of the applications support a -H switch on the command line that will list the configuration files it will look for and the directives in each one that it understands.

The snmp.conf configuration file is intended to be a application suite wide configuration file that supports directives that are useful for controlling the fundamental nature of all of the SNMP applications, such as how they all manipulate and parse the textual SNMP MIB files.

SWITCHING CONFIGURATION TYPES IN MID-FILE

It’s possible to switch in mid-file the configuration type that the parser is supposed to be reading. Since that sentence doesn’t make much sense, lets give you an example: say that you wanted to turn on packet dumping output for the agent by default, but you didn’t want to do that for the rest of the applications (ie, snmpget, snmpwalk, ...). Normally to enable packet dumping in the configuration file you’d need to put a line like:

dumpPacket true

into the snmp.conf file. But, this would turn it on for all of the applications. So, instead, you can put the same line in the snmpd.conf file so that it only applies to the snmpd daemon. However, you need to tell the parser to expect this line. You do this by putting a special type specification token inside a [] set. In other words, inside your snmpd.conf file you could put the above snmp.conf directive by adding a line like so:

[snmp] dumpPacket true

This tells the parser to parse the above line as if it were inside a snmp.conf file instead of an snmpd.conf file. If you want to parse a bunch of lines rather than just one then you can make the context switch apply to the remainder of the file or until the next context switch directive by putting the special token on a line by itself:

# make this file handle snmp.conf tokens:
[snmp]
dumpPacket true
logTimestamp true
# return to our original snmpd.conf tokens:
[snmpd]
rocommunity mypublic

COMMENTS

Any lines beginning with the character ’#’ in the configuration files are treated as a comment and are not parsed.

INCLUDING OTHER CONFIGURATION FILES

It is possible to include other configuration files for processing during normal configuration file processing.:

# include site specific config
include site.conf

This will search every directory in the configuration path for files
named site.conf, and will process those files before returning to the
processing of the original file. Note that if ’.conf’ is omitted,
it will be appended. That is, all configuration files must end
in ’.conf’.

API INTERFACE

Information about writing C code that makes use of this system in either the agent’s MIB modules or in applications can be found in the netsnmp_config_api(3) manual page.

SEE ALSO

snmpconf(1), netsnmp_config_api(3), snmp.conf(5), snmpd.conf(5)






Opportunity


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.





Free Software


Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.


Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.





Free Books


The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.


Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.





Education


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.


Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.